Blocks of peperino built in opus quadratum from the Republican period were used on the sides of the castle.
Later, in the 11th century AD, the Benedictines built the new walls with five towers of which four are still standing today. The Medieval tower, made of molten, and so-called La Rocca, was changed into a secret prison in the 16th century, as graffiti on the cell walls reveal.
In Piazza Carlo Fontana, we can still see the watchtower used as a signal post built in the 14th century to replace the previous one erected by the Benedictines, and destroyed in the raid by the Frangipane in 1300.
In 1564, Giuliano Cesarini of Civita Lavinia purchased the castrum after which was no longer used as a defence fortress.
The castle was partially destroyed by Allies during the Second World War and the upper floors were rebuilt straight after the war. The sequence of the different construction layers is still clearly visible today.
The remains of the castle have been incorporated into the houses of the historical centre.